Cache queue entry linking for DASD record updates
A data storage system provides disaster recovery capability by asynchronously transmitting record updates to a secondary site in sequence consistent order. Such record updates are stored at a primary site in a cache memo…
Original patent title: “Cache queue entry linking for DASD record updates”
What this patent covers
The actual claim
A data storage system provides disaster recovery capability by asynchronously transmitting record updates to a secondary site in sequence consistent order. Such record updates are stored at a primary site in a cache memory of a storage controller. A circular queue is created having a head pointer for locating a first (or oldest) record update with subsequent record updates of a track being linked therefrom in sequence consistent order. A tail pointer of the circular queue points to the last record update. A counter field is provided in a track slot header for counting a number of updated records in the track and hence the circular queue. When a data mover in the host processor at the primary site reads record updates for transmission to the secondary site, the data mover starts with the record update pointed to by the head pointer such that the data mover moves through the circular queue (and hence the record updates) in a backward chain fashion. The counter is decremented as each record update in the track is read by the data mover such that when the counter reaches zero the data mover knows that no other record updates exist for that track.
What this patent does NOT cover
The boundaries
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Patent Abstract
Patent abstract
A data storage system provides disaster recovery capability by asynchronously transmitting record updates to a secondary site in sequence consistent order. Such record updates are stored at a primary site in a cache memory of a storage controller. A circular queue is created having a head pointer for locating a first (or oldest) record update with subsequent record updates of a track being linked therefrom in sequence consistent order. A tail pointer of the circular queue points to the last record update. A counter field is provided in a track slot header for counting a number of updated records in the track and hence the circular queue. When a data mover in the host processor at the primary site reads record updates for transmission to the secondary site, the data mover starts with the record update pointed to by the head pointer such that the data mover moves through the circular queue (and hence the record updates) in a backward chain fashion. The counter is decremented as each record update in the track is read by the data mover such that when the counter reaches zero the data mover knows that no other record updates exist for that track.
Patent Journey
From filing to expiry
Patent Filed
1995
Patent Granted
1997 · 3yr after filing
Highly Cited
145 patents cite this
Patent Expired
2015
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
9/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assignee
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
The original legal language
Original claims
13 claims as filed with the patent office.
Citations
Patent lineage
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 12564871 · 2026
A Fixture for Cleaning Showerheads with Multiple Separate Chambers
This patent describes a cleaning device for showerheads that uses a fixture with three or more separate internal compartments and channels to direct cleaning fluid to the showerhead's upper surfaces.
ASM IP HOLDING BV
US 12324579 · 2025
Surgical Stapler Battery Health Check During Operation
This patent describes a powered surgical stapler that can detect if some of its rechargeable battery cells are damaged while it's actually firing staples, helping ensure the procedure finishes safely.
CILAG GMBH INT
US 12471982 · 2025
Surgical Tool That Combines Energy Treatment and Stapling
CILAG's patent details a surgical instrument that applies therapeutic energy to tissue, monitors its properties, then deploys staples, adapting the stapling based on the initial energy treatment and monitoring.
CILAG GMBH INT
US 11918209 · 2024
Real-Time Surgical Instrument Status on Live Video During Operations
This patent describes a surgical system that shows live video from inside the body and overlays important information about the surgical tool directly onto the screen, helping surgeons operate more precisely.
CILAG GMBH INT
US 8697359 · 2014
How to Use CRISPR-Cas9 to Edit Genes in Human Cells
This patent describes a method and system for precisely altering gene expression in eukaryotic cells, including human cells, using an engineered CRISPR-Cas9 system that targets and cleaves specific DNA sequences.
Massachusetts Institute of Technology
US 4683195 · 1987
How to Make Many Copies of a Specific DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a fundamental process for making millions of copies of a specific DNA or RNA segment from a tiny sample, enabling its detection.
Cetus Corp
Same assignee
More from International Business Machines Corp
Patent monitoring